oxygen environment, because that give you the same oxygen absorption at 27,000 feet with only five psi inside. with lower pressure, 100% oxygen, like you have the same oxygen intake that we have here on earth. that way, you could build a lighter spacecraft, did not need the structure because it was only five psi incident of the higher pressure you would want out there in the vacuum of space. the original spacecraft had no window except for a little port hole way over here on the left . you can just tell whether it was light or dark out of that. early on, the powers that be and nasa and people running the program agreed that we should put in a window, so they put a window in that came right up over the astronauts's head. they used to call it a capsule. i have referred to that already a couple of times here we later. -- of times here. we later came around to describing it as a spacecraft. bob hope said it was the first time in history a capsule had taken a man. [laughter] john glenn: another thing that people were surprised about is originally nasa had a rule that prohibited any camera f